Die for punching data processing cards, tapes and the like



H. MAHN Sept 13, 1966 DIE FOR PUNCHING DATA PROCESSING CARDS, TAPES AND THE LIKE Filed NOV. 17, 1964 INVENTOR.

HERBERT MAHN United States Patent "ice 3 Claims. (in. 83--578) In data processing cards, holes are punched in lines or columns by means of a single matrix or in blocks by means of a full matrix in which a punching die is associated with each possible hole to be made in the entire card. The punching dies or needles are invariably controlled through an electromagnetic mechanism.

The cards to be punched are moved in a stepwise manner with the single matrix as well as the full matrix. However, the rate of stepwise movement of the punch cards is limited by the rate of punching. The latter is determined by the fact that, during the engagement of the punching die, the punch card cannot move without damaging the sensitive card.

According to the invention the punching die has a shape such as to perform a punching operation during the forward movement as well as during the backward movement, the card while uniformly moving forwards running into a recess of the die shaft during the reversal of the movement of the die from forwards to backwards. The card is thus not checked in its movement by the die.

In order that the invention may be readily carried into effect, it will now be described in detail, by way of example, with reference to the accompanying diagrammatic drawing showing, in FIGS. 1-5 successively, the individual phases of a punching operation as the die is moved to and fro.

Referring to FIGS. 1 and 2 the punching surface 1 of the die 1 has the width of the standardised card hole, but only half the length thereof. At a given instant, which is determined by the forward movement of the card and the control pulse, the die 1 punches in known manner a hole in a card 2 with respect to a matrix 3. This hole made by removing a piece is thus only approximately half the length of the standard size.

During the reversing movement of the punching die (FIGS. 3 and 4), which cannot take place in an arbitrarily short time due to the consequent accelerations of the mass of the drive for the punching die, the card 2 continues to move in the direction of the arrow and a cut edge runs into a recess 4 of the die shaft (FIGURE 3).

During the return movement of the punching die 1, a

3,272,052 Patented Sept. 13, 1966 second chip or piece 6 of the card is punched to the prescribed length against the cutting edge of a die guide 8 by means of a punching surface 1" (FIGURE 5).

Shortly thereafter the punching die 1 has again reached its initial position (FIGURE 5).

The edge a of the punching surface (FIGURE 5) would have to be as small as possible since, on the one hand, it determines the depth of penetration of the punching die 1 through the card 2 and, on the other hand, it must not damage the card when passing through it in its backward (upward) movement.

The surface a as well as the cross-sectional dimensions at b and c are determined by the quality of the material used for the die.

With optimum shaping the cross-section at b must be wedge-shaped and increase towards the cross-section c. The punching surface 1" which thus has an inclination a and is active during the backward movement of the die will exert a laterally cutting action as the card 2 runs in.

The waste material 6 produced in punching on the return movement is drawn off or blown off, for example, from a duct 7 in the die guide 8.

According to the invention it is possible, if a plurality of such new punching dies is provided, to punch in columns by means of single matrix or in blocks by means of a so-called full matrix. Essential is the continuous movement of the punch card or the like through the punching device which is rendered possible by the said shape of the punching die.

What is claimed is:

1. A die for punching data processing cards, tapes and the like comprising, a punch and guide, said punch having a cutting surface at one axial end of said punch, a laterally extending recess in said die, a second cutting surface on said punch defined by the edge of said punch extending between said cutting surface and the adjacent surface of said recess, and a second recess in said guide positioned for communication with said punch recess in the inoperative position of said punch.

2. A die according to claim -1 wherein said adjacent surface of said die is inclined inwardly.

3. A die according to claim 2 wherein the surfaces defining said recess are curvilinear for chip ejection.

References Cited by the Examiner UNITED STATES PATENTS 1/1958 Lang 83578 12/1959 Kinkaid 83578 

1. A DIE FOR PUNCHING DATA PROCESSING CARDS, TAPES AND THE LIKE COMPRISING, A PUNCH AND GUIDE, SAID PUNCH HAVING A CUTTING SURFACE AT ONE AXIAL END OF SAID PUNCH, A LATERALLY EXTENDING RECESS IN SAID DIE, A SECOND CUTTING SURFACE ON SAID PUNCH DEFINED BY THE EDGE OF SAID PUNCH EXTENDING BETWEEN SAID CUTTING SURFACE AND THE ADJACENT SURFACE OF SAID RECESS, AND A SECOND RECESS IN SAID GUIDE POSITIONED FOR COMMUNICATION WITH SAID PUNCH RECESS IN THE INOPERATIVE POSITION OF SAID PUNCH. 